Battery Test

BATTERY BUILT-IN TEST INDICATOR

Built-In Test Indicator Sight Glass:

Battery Construction And Test Indicator:

Test Indicator:

Test Indicator
The Test Indicator measures the specific gravity of the electrolyte. Specific Gravity (SG) of the electrolyte will show state-of-charge (voltage). The test indicator WILL NOT show cranking capacity of the battery. Refer to Starting and Charging/Battery/Testing and Inspection/Procedures/Battery Load Test for more information. Look into the sight glass and note the color of the indicator. Refer to the following description of colors:

The battery is adequately charged for further testing and may be returned to use. If the vehicle will not crank for a maximum 15 seconds, refer to Starting and Charging/Battery/Testing and Inspection/Procedures/Battery load test.

NOTE: BLACK OR DARK = 0 to 75 % state-of-charge

The battery is INADEQUATELY charged and must be charged until green dot is visible, (12.4 Volts or greater) before the battery is tested or returned to use. Refer to Causes of Battery Discharging.

NOTE: CLEAR COLOR = Replace Battery

WARNING: DO NOT CHARGE, ASSIST BOOST, LOAD TEST, OR ADD WATER TO THE BATTERY WHEN CLEAR COLOR DOT IS VISIBLE. PERSONAL INJURY MAY OCCUR.

A clear color dot shows electrolyte level in battery is below the test indicator. Water cannot be added to a maintenance free battery. The battery must be replaced. A low electrolyte level may be caused by an over charging condition. Refer to Starting and Charging/Charging System/Alternator/Generator Test Procedures on Vehicle.

Causes Of Battery Discharging
It is normal to have a small (5 to 25) milliamperes continuous electrical draw from the battery This draw will take place with the ignition in the OFF position, and the courtesy, dome, storage compartments, and engine compartment lights OFF. The continuous draw is due to various electronic features or accessories that require electrical current with the ignition OFF to function properly When a vehicle is not used over an extended period of approximately 20 days the IOD fuse should be pulled. The fuse is located in the Junction Block. Disconnection of this fuse will reduce the level of battery discharge. Refer to Starting and Charging/Battery/Testing and Inspection/Procedures/Battery Diagnosis and Testing Chart and to the proper procedures.

Abnormal Battery Discharging
- Corroded battery posts, cables or terminals.
- Loose or worn generator drive belt.
- Electrical loads that exceed the output of the charging system due to equipment or accessories installed after delivery.
- Slow driving speeds in heavy traffic conditions or prolonged idling with high-amperage electrical systems in use.
- Defective electrical circuit or component causing excess Ignition Off Draw (IOD). Refer to Starting and Charging/Battery/Testing and Inspection/Procedures/Battery Ignition Off Draw (IOD).
- Defective charging system.
- Defective battery.

BATTERY IGNITION OFF DRAW (IOD)
High current draw on the battery with the ignition OFF will discharge a battery. After a dead battery is serviced the vehicle Ignition Off Draw (IOD) should be checked. Determine if a high current draw condition exists first check the vehicle with a test light.
1. Verify that all electrical accessories are OFF.
- Remove key from ignition switch
- Turn off all lights
- Trunk lid and glove box door is closed
- Sun visor vanity lights are OFF
- All doors are closed
- Allow the Illuminated Entry System to time out in approximately 30 seconds, if equipped.
- During Transmission Control Module (TCM) power down there will be 500 milliamperes present for 20 minutes. Afterwards less than 1.0 milliampere.

Disconnect Battery Negative Cable:

2. Disconnect battery negative cable.

CAUTION: Always disconnect the milliampere meter before opening a door.

Milliampere Meter Connection:

3. Using an multi-meter, that has least a milliampere range of 200 mA. Set meter to the highest mA range. Install meter between the battery negative cable and battery negative post. After all modules time-out the total vehicle IOD should be less than 25 milliamperes. If ignition off draw is more than 25 milliamperes go to Step 4.
4. Each time the milliampere meter is disconnected and connected, all electronic timer functions will be activated for approximately one minute. The Body Control Module (BCM) ignition off draw can reach 90 milliamperes.
5. Remove the [1][2]PDC fuses:
- Interior lamps
- Brake lamp
- IOD
6. If there is any reading, with fuses removed there is a short circuit in the wiring. If reading is less than 25 mA go to Step 8.
7. Install all fuses. After installing fuse, the current can reach 90 mA. After. time-out the reading should not exceed 25 mA. If OK go to. If not, disconnect:
- Radio
- Body control module
- Remote keyless entry module
8. Disconnect one component at time, to see if any component is at fault. If the high reading is not eliminated there is a short circuit in the wiring.
9. Remove interior and brake lamp fuses. Install the fuses. The milliampere reading should be 2-4 mA. If reading is higher than 4 mA:
a. Disconnect PCM.
b. If reading is OK, replace PCM.
c. If reading does not change, disconnect the TCM.
d. If reading is OK, replace TCM.
e. If reading stays, there is a short circuit to one of the modules.

BATTERY LOAD TEST
A fully charged battery must have cranking capacity, to provide the starter motor and ignition system enough power to start the engine over a broad range of ambient temperatures. A battery load test will verify the actual cranking capability of the battery.

WARNING: IF BATTERY SHOWS SIGNS OF FREEZING, LEAKING, LOOSE POSTS, OR EXCESSIVELY LOW ELECTROLYTE LEVEL, DO NOT TEST. ACID BURNS OR AN EXPLOSIVE CONDITION MAY RESULT.

1. Remove both battery cables, negative cable first. The battery top, cables and posts should be clean. If green dot is not visible in indicator, charge the battery. Refer to Starting and Charging/Battery/Battery Charging Procedures.

Volt - Ammeter Load Tester Connections:

Remove Surface Charge From Battery:

2. Connect a Volt/Ammeter/Load tester to the battery posts. Rotate the load control knob of the Carbon pile rheostat to apply a 300 amp load. Apply this load for 15 seconds to remove the surface charge from the battery, and return the control knob to off.
3. Allow the battery to stabilize for 2 minutes, and then verify open circuit voltage.

Load 50% Cold Crank Rating:

4. Rotate the load control knob on the tester to maintain 50% of the battery cold crank rating for 15 seconds. Record the loaded voltage reading and return the load control to off. Refer to the Starting and Charging/Battery/Specifications/Battery Specifications.

Battery Load Test Temperatures:

5. Voltage drop will vary according to battery temperature at the time of the load test. Battery temperature can be estimated by the temperature of exposure over the preceding several hours. If the battery has been charged or boosted a few minutes prior to the test, the battery would be slightly warmer. Refer to Load Test Voltage Chart for proper loaded voltage reading.

6. If battery passes load test, it is in good condition and further tests are not necessary If it fails load test, it should be replaced.

BATTERY OPEN CIRCUIT VOLTAGE TEST
An open circuit voltage no load test shows the state of charge of a battery and whether it is ready for a load test at 50 percent of the battery's cold crank rating. Refer to Starting and Charging/Battery/Battery Load Test. If a battery has open circuit voltage reading of 12.4 Volts or greater, and will not pass the load test, replace the battery because it is defective. To test open circuit voltage, perform the following operation.
1. Remove both battery cables, negative cable first. Battery top, cables and posts should be clean. If green dot is not visible in indicator, charge the battery. Refer to Starting and Charging/Battery/Battery Charging Procedures.
2. Connect a Volt/Ammeter/Load tester to the battery posts. Rotate the load control knob of the Carbon pile rheostat to apply a 300 amp load. Apply this load for 15 seconds to remove the surface charge from the battery, and return the control knob to off.

Testing Open Circuit Voltage:

3. Allow the battery to stabilize for 2 minutes, and then verify the open circuit voltage.

Battery Open Circuit Voltage:

4. This voltage reading will approximate the state of charge of the battery. It will not reveal battery cranking capacity.